


mission: baby Peter

by CheekSmile



Category: Marvel Cinematic Universe, Spider-Man (Tom Holland Movies), The Avengers (Marvel Movies)
Genre: Age Regression/De-Aging, Avengers Family, De-Aged Peter Parker, Gen, Kid Peter Parker, Nightmares, Other Additional Tags to Be Added, Peter Parker Needs a Hug, Precious Peter Parker, Protective Avengers, Protective Tony Stark, Sick Peter Parker, Sleepy Cuddles, Tony Stark Acting as Peter Parker's Parental Figure, Tony Stark Feels, Tony Stark Has A Heart, Tony Stark Needs a Hug
Language: English
Status: In-Progress
Published: 2019-08-06
Updated: 2020-08-06
Packaged: 2020-08-10 14:50:33
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 12
Words: 18,299
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20137240
Author URL: https://archiveofourown.org/users/CheekSmile/pseuds/CheekSmile
Summary: May Parker thinks that the wierdest thing that can ever happen in someone's life is being the Aunt of a teenager superhero.But when she goes back home one night and suddently that teenager is not a teenager anymore and she has to turn to the Avengers for help... she changes her mind.aka Peter gets de-aged by an unknown substance and Tony Stark has to find a cure before that substance also kills him, with the help of the other Avengers.THIS IS MY FIRST FANFIC EVER AND ENGLISH IS NOT MY FIRST LENGUAGE, so please be kind, but also help me by giving adivices and correcting my errors :)





	1. my nephew's mini-vesion

**Author's Note:**

> hi guys!  
as you know ( I mean how could you have missed the capital letters ) this is my first work, but I hope you'll enjoy it anyway.  
I don't have a posting schedule an it might take me a while tu update (I know, I hate it too, it sucks) so I just wanted to say sorry.
> 
> Aaaaand here you go with the first chapter!

Chapter 1

That night, when she went back home, May found her usual cosy living room and her messy kitchen, surrounded by a familiar silence.  
It was 2 AM, she had just finished her shift at the hospital and she was exhausted.  
She let herself fall on the couch, closing her eyes for a few seconds, enjoying the softness of the old sofa.  
When she reopened them, she noticed that the bathroom light was on and came out through the hairline crack between the floor and the wooden door.  
She stood up, heading to her nephew's bedroom and check on him: maybe Peter forgot to switch the light off because of his tiredness, she thought.  
The bedroom door was open, showing that there was no one curled up under the comforter of the bunk bed at the bottom of the room.  
Concerned, Aunt May knocked softly at the bathroom door:

“Peter, sweetheart, are you in there?”, she asked.

No answer.

Frowning, the woman looked again at the clock. No, it was 2.20 AM, way to late for Peter to still be out partolling around Queens.

“Peter?” she tried again, voice soft, and, when she newly obtained only silence, she opened the door, just in time to see her nephew, pale as a sheet and sweaty, kneeled in front of the toilet bowl, puke is guts out.  
Peter was panting, fat tears flowed down his cheeks and on his face there was a pained frown.  
Without hesitation, May kneeled beside him, rubbing his back to comfort him.

“Shh, it's alright” she whispered in his ear.  
The only answer she got was a weak whimper, followed by another wave of vomit.  
They stayed like that for almost half an hour, and after three other puking waves May stood up, coming back less than a minute later with a blanket and a glass of water.  
She wrapped the fifteen-year-old in the blanket, leading him gently to lean against the wall, then she gave him the glass, that he took with trembling hands and drank gratefully.

“May...” he whined with weak voice, almost a whisper.

“I now, I now”, she whispered back enveloping him in a careful but sweet hug, “ It'll be over soon, don't worry.”.

But it wasn't as she said.

Peter was sick for the whole night, but he was able to tell his Aunt, somehow between a sob and another, that everything had started after a masked mugger had stabbed him in his stomach, making him come back home earlyer.  
May checked on the wound, it wasn't deep, but it was covered by a blue liquid, probably left by the blade that caused it.  
Eventually, though, at around 6 AM, Peter crashed out, a bit because of the exhaustion and a bit because of the pain he felt after puking more than 13 times.

That's when the things really started to go wrong, that is, way more wrong than you could ever think.

Peter was once again leaned against the wall, head rested on his Aunt's shoulder, seated beside him, that was whispering to him comforting words, while she ran her hands through his curly hair.  
Out of nothing, Peter began to fidget in his sleep: he was panting, while fat tears wetted his cheeks, and moaning weakly. May didn't know what to do, she couldn't understand the cause of he nephew's sudden agitation, till she noticed that big bubbles were forming under his pale skin and they begun to move all around the boy's body.  
Suddenly, Peter began to become smaller under his Aunt's disbelieving graze. He was de-aging, she noticed while she tried to calm her increasingly smaller and sobbing nephew.  
Then the process stopped like it had started, leaving May to cuddle a two-year-old version of Peter.  
She shook her head and squeezed her eyes shut, but when she reopened them the seen in front of her was the same as before: a toddler wrapped in a blanket was sleeping in her arms, with a relived expression on his tiny, chubby face.  
Understanding that there was no reason to stay in the bathroom anymore, the woman stood and went back in the living room, she carefully laid Peter down on the couch and reached for her phone.

She knew exactly who to call in this situation.

Tony had been working in his lab on his new suit for a few hours by now. He was proud of the progresses he made and he was about to check on the last things when FRIDAY switched the background AC DC music off to tell him something important:

“Sir, May Parker has been trying to contact you for several minutes.”

“You heard me, FRI, I specifically told you that I don't want to be disturbed today, I'm working on something important.”

“I'm sorry, but she keeps insisting, it seems very important.”  
Tony sighed. Truth to be told, he knew May hardly ever phoned him -that, and that she would keep trying to reach him until he answered- so he was beginning to feel slightly concerned.

“Fine, put her trough.”  
less than a second later, May's voice filled the room.

“Tony, is that finally you?” She was whispering, but the urgency was clear.

“Hi May, what's up?”, he answered casually, trying to ignore the growing concern inside of him.

“It's Peter, something happened to him. You... won't believe me, but... gosh, I don't even know how to explain this... he got de-aged, Tony.”, the man in question frowned, thinking that he had misunderstood.

“Come again?”

“You heard me and I swear it's the truth. I know it's incredible, but... I was there when it happened. He came back yesterday evening and he was wounded, he was really sick and when this morning he fell asleep... You'll think it's a joke, but now he is sleeping on the couch and he seems a two-year-old!”

“Okay, May. Calm down.” Tony sighed trying to fully understand what he was just told. “Bring him here. We'll see what we can do to help. I'm sure there has to be something, don't worry.”

“Thank you, really.” the woman answered gratefully. “I didn't know what to do”

“Don't sweat it. See you soon?”

“Yeah, we'll be there in half an hour. Bye.” she said and then she hung up, leaving Tony in the silence.


	2. Doctor Bruce and Tony to the rescue!

**Summary for the Chapter:**

> May and little Peter go to the Avengers compound.

Chapter 2

“Sir, May and Peter Parker have just arrived”

“Send them here, FRIDAY”, Tony replied while he disposed some tests on the medbay counter. Meanwhile Bruce had put his white coat on and was looking for a stethoscope in the drawer.  
A few minutes later a very worried and tired Aunt May entered the room whit an asleep toddler in her arms.  
He was small and had light brown, curly hair, chubby cheeks and was sucking his thumb in his sleep.

He was definitely Peter.

“Hi, May. Please, take a seat on this bed.” Bruce greeted pointing at the hospital bed he had prepared. May did as she was told and the doctor approached.

“Tony told me about a wound, can I see it?” He asked with a gentle tone, minding not to wake the child up. The woman nodded, rearranging her grip on Peter so that he was leaning on her arm, and she pulled his t-shirt up -luckily she had conserved some of her nephew's little clothes as a memory- revealing the wound.  
Ti was still angry red an covered by that liquid as it was the previous night and this surprised everyone, because, thanks to the spiderling's healing factor, it should have at least closed a little bit.

“Is it serious?” Tony spoke for the first time, approaching to have a better look.

“I don't think so, but I'll have to take a stamp of the substance that covers it: it's probably the cause of what happened.” Bruce answered taking a cotton swab and collecting some of the blue liquid.  
There was a sudden whine from the toddler, immediately hushed by May that rocked him back and fort gently.  
While Bruce put the stamp in a machine, Tony spoke again:

“Does he remember us? Does he know what happened to him?”

“I'm not sure, He woke up only once and for a couple of minutes, he called me by my name, but I couldn't understand if he is conscious of the situation.” Aunt May answered. 

“Well”, Bruce said, “ Since he is sleeping we may as well patch him up and when he wakes up we can figure the psychological part of the issue out. Sounds great?”

“Yeah, sounds like a good idea.” Tony said. And so the doctor began to clean the wound with some cotton and disinfectant, but Peter, clearly not happy about it, began to squirm and whine in his sleep and it took both May and Tony to keep him still enough for Bruce to bandage his little stomach in a gauze. At the end of it, though, the toddler was so distressed that his eyes snapped open and he began to cry.

“Hey, Peter. Hush, it's all over now. You did very good, you know? Very very good.” Tony said trying to get the toddler's attention to make him stop crying.

“Tony is right, baby. You were so brave!” May said and at that words Peter's face lighted up with pride and he calmed down, beginning to be aware of his surrounding.

“'Ony!” He said when he met the man's graze, pointing at him with his little hand, that the genius took making the child giggle.

“Hi there, Pete!” he answered smiling, relived that the toddler remembered who he was.

“B'uce!” the child went on, looking at the scientist, that smiled too and approached.

“Hello, Peter. I'm happy you remember us. I just want to make a little check up on you, so we can see if you are okay. May, please, can you put him on his feet on the bed?” May did as she was told and helped the child to stay upright alone until he found his balance.

“Great”, the doctor said, “Now why don't you walk to Tony, Peter? He is right at the end of the bed” Peter nodded smiling and slowly walked towards his mentor. At a few inches from the border, though, he lost his balance and fell forward, but luckily Tony was ready to catch him before he touched the ground. Peter looked at him in shock, with two fingers in his mouth and tears welling up in his eyes. The man's eyes widened at the sight and he hurried to comfort him.

“it's alright: I gotcha, kid”he said, internally panicking because he had no idea of what to do if the child started crying again. But instead the toddler threw his arms around Tony's neck and latching on him like a koala bear. May cooed:

“Aww, he is behaving just like when he was small”

“Well, that's what we are trying to understand, May.”, Bruce explained, “Is there a teen-Peter in there, or not? His teenager mind is stuck in a baby body, or that got de-aged, too?” 

“That's a great question” she observed.

“How do we understand that?” Tony asked while he rubbed Peter's back.

“We can try with some simple questions.”, Bruce suggested, “Peter?” he asked trying to get his attention. The child tuned his head towards the scientist, without loosing his grip on Tony.

“What's six plus two?” Peter looked at him and tilted his head, obviously confused.

“Okay...”, Bruce said scribbling something on his notebook, “And... What did you do yesterday?”

“School!” Peter said, bouncing happily in Tony's arms, proud to be able to answer. Then he suddenly stopped and his eyes widened, like he just remembered something important. He pulled up his t-shirt and looked down exactly where his wound was.

“Oh no!” he whispered, his eyes welled up with tears, but before he could start to cry, May intervened:

“Everything's ok sweetie: Bruce patched you up while you were sleeping, so in a few days you'll be all new, you'll see.”

“Bad guys.” Peter explained looking up at Tony, who looked like he didn't know what to say back, so May went on:

“That's right, some bad guys did that to you. Do you remember them?” Peter scrunched his face in concentration, then his expression fell in a mortified one.

“No...” he said.

“That's ok.” Tony hurriedly said, hating when his protègè was anything but happy, “It doesn't matter, we will catch them anyway, don't worry about it.” 

And in that exact moment, the analysis machine began to beep, indicating that it had finished his job.

**Notes for the Chapter:**

> Aaaaand this was the second chapter.   
What do you think? How cute is little Peter I'm melting 😍!!


	3. Who's my sleepy spider?

**Summary for the Chapter:**

> The adults have a talk and Peter is left with Tony. Tears and fluff occours.

Chapter 3

About an hour later, the four of them were seated on the couch in the compound's common room, Peter once again fast asleep in his Aunt's arms thanks to her coddles. 

“...Concluding,” Bruce was saying, “thanks to all the tests we ran, Tony and I now understand that Peter de-aged because of the substance in his wound that was left behind by the blade. We figure that the only purpose of it was to weaken Peter's immune system and, in general, all of his vital functions by transforming him into a toddler so he would be more vulnerable.”

“So basically you’re saying...”, May clarified, “... That Peter is in serious danger!? That all this is life-threatening!?” Bruce hesitated, his expression faltering a bit.

“Not 'serious', but yes. In danger.”

“That's terrible! You have to help him!”

“And we’re already on it, May.” Tony reassured her, “We synthesized an antidote that should at least be able to stop the poison from affecting Peter's body any further and we are working on something that will reverse its effects, but we'll need some more time. We only have to hope that this poison isn't so advanced to evolve and defeat the antidote before we can find a permanent solution, but even then we have it covered; FRIDAY is constantly working on an antibiotic stronger than this one and I'll help her when I can.”

“Thank God.”, the woman said, “And what about his brain?”

“Peter seems to have the brain of a two-year-old, maybe three, but all his memories are still there.” Bruce said. May nodded and then she turned her head to look at the clock above the fireplace.  
It was 10:50 a.m. 

“Tony...”

“Yes, May?”

“I'm sorry I have to ask you this, but... could you take care of Peter while he is like this?” Tony's eyes widened in surprise.

“What!? I can't take care of him, I don't even know how to take care of a kid! I'm not cut out for this kind of thing.”

“Oh, don't be so dramatic.” she said, “Peter is a kind and polite boy, he always has been. Plus, I have to work all day long, not to mention I get back home at two in the morning! Children need attention and constant supervision, I can't leave him alone, God knows he already spends too long on his own it that apartment as a teen.”

“No. I'm sorry, really, but I can't.” I can't risk screwing this up like everything else, he thought. Because that's what he really feared; would he be enough, what if he did something wrong, or worse, what if he were to end up like his father? The same father that was the cause of his doubts in that moment, because if that man had been around, if he had only showed some interest in him, maybe Tony wouldn't be this scared of being a father himself – because that's what May was asking of him.  
Plus, he broke everything he touched, he was a disaster in human relationships and having Peter around as a teenager was already too much of a risk that he would ruin the teen’s young and careless life.

“I know what you're thinking, Tony,'' Bruce broke through his thoughts, “And it's not true. You're not like him, you're way better; you did pretty good in the medbay with Peter, you knew exactly what to do.” 

“That was different! It was just one moment and you were there, too.”

“You won't be alone, Tony. Here at the compound there are all of the Avengers including Pepper and I'm sure everyone will be happy to help.”

“You can do it. Plus, It's better for Peter to stay here for the antidote, right?”, May tried to convince him, “You wouldn't want him to stay alone all day, would you?”

“Of course not...” Tony said, then sighed and ran his hands through his hair, thinking about the situation for a minute.

“Okay, I'll keep him with me.” He said finally. May gave him one of her smiles that would warm anyone’s heart.

“Thanks, Tony. Really.”

“Don't sweat it” he murmured, knowing that he was going to regret this soon.  
.  
.  
.

Peter woke up a few hours later.  
It took him a while to understand where he was before he realized, with a little bit of disappointment, that he wasn't in his Aunt's warm arms any more. Instead he found himself in the middle of a big bed, covered by a blanket and surrounded by pillows.

Confused, he sat up and quickly realized he was the only one in the room.  
Still a little disoriented due to his sleepiness, he stood up on the bed trying to understand where he was.  
He began to whimper, scared and lost, bringing his thumb to his mouth.

He was all alone in who knows where. Had he been abandoned? Had he been a bad boy? Did that mean that he didn't have anybody left?

No.

No no no no! That couldn't be possible.

Fat tears began to fall on his cheeks and he started sobbing.

He tried to take a step forward to find someone, but the softness of the mattress made him lose his balance causing him to fall on his face instead. All he could think to do was to curl in on himself and cry harder than before.

.  
.  
.

Tony was in his workshop again.  
Peter had been asleep since May left and he wanted to take advantage of this alone time -he knew he wasn't going to have a lot of it with a toddler around- to strengthen the antibiotic and find a way to bring Peter back to his teenage self as soon as possible. If he was being honest with himself, having a little version of his protègè around terrified him. A lot. It was better if he fixed all of this in general.

“Sir, Peter is awake and seems to be in distress.” FRIDAY interrupted his thoughts. Tony sprang to his feet, forgetting what he was working on, speed-walking to his bedroom where he had put Peter to let him rest.

“Can you be more specific, FRI?”

“Peter is crying for unknown reasons.”

“Okay, thanks.” Tony replied, breathing in to calm himself before opening the door slowly so as not to startle the boy further.  
In the middle of his bed he saw the toddler, curled in on himself in an attempt to self-soothe as he continued to cry with his face buried in the blankets.  
The billionaire's face softened without losing the shadow of concern; in that moment he realized just how small and fragile Peter had become. The sudden change of perspective caused a shiver to travel down his back.  
Putting those thoughts aside, the man slowly approached the bed and then sat down, beginning to rub the child's back.

“Hey Peter.” he whispered with the most gentle tone he could muster “What happened, buddy?”

The toddler turned his head toward the voice and, when he was met with the familiar face of his mentor, crawled frantically toward him, climbing to the man's neck and latching on.  
Tony welcomed the child in his arms and began to rock him softly, whispering comforting words.

“Shh, shh, it's alright. I'm here. No need to cry, kiddo.”  
Slowly, Peter's sobs became occasional hiccups as his breathing settled.

“Do you wanna tell me what happened?” Tony tried.

“A-alone.” Peter whispered.

Oh.

Right. He should have thought about that. Peter got scared because when he woke up there was no one with him. In that moment the genius billionaire playboy philanthropist in that also felt stupid; he should have kept the toddler with him, and not put him in a room he wouldn’t even recognize!

“I'm really sorry, buddy. It's all my fault. I won't leave you alone any more, okay?”

“Any 'ore.” Peter repeated in a whisper, his head still rested on his mentor's shoulder. And in that moment Tony understood many of the kid's behaviours he had ignored in the past -how he always sought physical contact by brushing his arm with Tony's while they worked, or purposefully sitting very close to him during their movie nights, even the constant talking... It was all to fill the loneliness and the anxiety of being abandoned.

“'Ony don't go?” the child asked with hope in his voice, interrupting the genius's thoughts. “Like Mommy and Daddy and Ben?”

At those words Tony tightened his grip on the toddler, almost squeezing him too much, and rested his head on the child's fluffy head of hair.

“I promise I'll stay” he said, even if he knew that, in his line of work, that could be a difficult promise to keep. He would try. If only for his kid.

For Peter.

**Notes for the Chapter:**

> Wow guys writing from the POV of a Two-year-old is difficult (who knows what's in their little heads?) so sorry if that part is a bit bad. 
> 
> Anyway.. Thanks to lefierro for helping me by editing this chapter and hopefully all the future ones (It's a really good job, admit it) ❤
> 
> And I posted this chapter from my phone because I'm on a trip, so tell me if there's something wrong. 
> 
> See ya next time😊😊


	4. Let's eat pizza!

**Summary for the Chapter:**

> the other avengers currently in the tower meet baby Peter

Chapter 4

It took 20 minutes for Peter and Tony to break their hug.  
Finally calm and glancing around curiously, the billionaire carried the child to the kitchen. There they found the one and only Hawkeye chewing on a poptart while flipping mindlessly through TV channels. 

“Clin'!” Peter shouted excitedly, squirming out of Tony's embrace -who almost had a heart attack from nearly dropping the kid- and ran, slightly unbalanced, towards his (kind of) teammate.  
Luckily, all the Avengers had been informed of Peter's situation via FRIDAY, so Clint wasn't surprised by the presence of a toddler stumbling up to him in the compound.

“Oh hey, bud!”, the archer grinned, “come here! I was about to watch some tv, would you like to join?”

“Yes! Yes!” Peter answered excitedly as Clint settled on a random children’s channel.

“So... de-aging huh?” Clint asked looking towards Tony without losing focus on the bouncing toddler immersed in an apparently very interesting show on his lap. Tony hummed non-committedly as he began to look for something edible to have for lunch considering it was already half past noon.

“Don't talk to me about it,'' sighed the genius, “By the way, I really hope you’re willing to give us some advice here, since you’re the only dad we have here.” 

“Do we know who did this?”

“Nope. FRIDAY is still analyzing the footage in the kid's suit looking for something significant. The only thing Peter told us -well, told May- is that it was some guy with a knife.” Tony replied while he took out some pasta and a pot from the cupboard, “ Do you know who will be honoring us with their presence for lunch?” He asked, changing the topic to something he could do now.

“Well... Cap is out of town to 'run an errand' for his buddy Fury, Sam and Rhodey are on a mission somewhere in Alaska, and Wanda and Vision are in Europe playing lovers, so I think it’ll only be us three and Bucky, Nat, and Bruce.

“Okay... Pasta should be good then.” Tony concluded.

“NO!” The two men were both shocked when Peter's high pitched scream echoed in the room.

“No?”, Tony asked looking at the child, “You don't want pasta?”  
Peter shook his head firmly.

“What do you want, then?”, The genius asked.

“'izza.”

“You want pizza?” Asked Clint, to which Peter frantically nodded his head in response.

“Well, okay, pizza it is then.”, Tony concluded, “FRIDAY, ask everyone what pizza they want and order a pepperoni for me. Clint, you want a bacon spinach, right?”, the archer nodded, “And, well, we don't wanna upset that little stomach of yours with strange toppings, Pete, so it's a margarita for you.” he looked at Clint again for an agreement on his choice and, when the man gave him a thumbs-up, he told FRIDAY to have all of the food delivered in 20 minutes max.  
Peter was now smiling and happily clapping his hands, having obtained what he wanted. Clint adjusted him on his lap, helping him not to fall off by steadying him, and smiled to himself.

Tony was putting the glasses on the table when Natasha entered the room, Bucky on her tail and carrying two heavy-looking boxes.

“We went shopping for the little twerp. Figured he didn't have fitting clothes anymore.” Nat said eyeing Tony, “With your money, of course; the child is yours after all.”

“Yeah, the cashier was a little dumbfounded.” Bucky added.  
Tony smirked thinking about the face of the poor woman that had to assist none other than the Black Widow and the Winter Soldier with everything necessary for a two-year-old that, knowing his teammates, would probably be enough for five children.

“What did you buy?” Clint asked.  
In a very short time, the room was filled with sippy cups, overalls, pacifiers, matching t-shirts, pants, socks and shoes, a high chair, every kind of toy you could think of, a crib, jackets, an avenger themed scarf, gloves and hat, some diapers -May told them that Peter was able to use the potty, but precautions never hurt- and many other things that they probably didn’t even need.  
Peter looked on in amazement at everything that was scattered on the floor and tried to run over to play with something when Tony put a hand on his shoulder to stop him.

“Uh-uh. All these things need to be cleaned first; we don't want to risk you getting sick, bud.”

“Don't you think you’re over exaggerating, Tony?” Bucky asked.

“No, he isn’t.”, Bruce said as he entered the room, “Peter's immune system is currently nonexistent. If he got sick, even a common cold could be a serious problem.”

“You heard the doc, Pete,'' Clint said while he placed the child back on his lap to keep him still, “No toys. They have to take a bath first.”

“Oh...” the child answered visibly saddened.

“But since we’re all here now, we can eat pizza!” As if on cue, the elevator doors opened revealing a dumb-founded pizza guy, to whom Tony immediately gave the required amount plus a tip before taking the pizzas and bringing them to the table.

“'izza!” Peter screamed. Bucky chuckled at his excitement as he placed him in the new high chair.

While they all ate, various casual conversations took place, till Nat spoke up with a question for Bruce.

“What about his spidey powers?” the room fell silent.

“Uh?”

“Earlier you said that Peter's immune system is nonexistent. Is it the same for his powers?”

“Oh. I believe his powers are in a dormant state as most of his energy is focused on fighting off the residual poison in Peter's body, but they will more than likely reappear one at a time as his body continues to dilute the toxin. So the more the poison is internally neutralized, the more energy he will have for his mutated cells to focus on his powers.”

“And when the poison is neutralized,'' Clint begins, “He just... grows up again? Puff and that's it?”

“Well, first of all, we still have to find an antidote that can help Peter's powers work against the substance. As of right now we’ve only been able to synthesize something that can keep the effects from worsening which will, unfortunately, lose its effectiveness over time. Once we find an actual solution, I have two theories about the outcome; the first one is that the poison will be completely neutralized all together leaving Peter to go through the same process as the first transformation,” Tony grimaced, remembering what May had told him and imagining a two-year-old puking his guts out all night waiting for the effects to reverse, “and the second one, that I personally find more probable, is that the poison will gradually filter out from Peter's body and, the more it does so, the more Peter will age and go back to his fifteen-year-old self. If this is the case, we assume he would only grow while he is asleep, since that will allow his body to focus solely on that.”

“How long would it take?” Tony asked.

“It depends on how long his body takes to fight off the toxin, but knowing his metabolism I think about a week or so would do it.”

“So you’re saying that, once you find the antidote, we’ll wake up with a different Peter of a different age and height every single day?” Bucky clarified. 

“Theoretically... yes.” Bruce admitted looking a little sorry.

“Fantastic. That’s great. We are so screwed.” Tony sighed, putting his head in his hand, “It will be like dealing with a different child every day. I have yet to figure teen-Peter out and let's not mention his baby form, about whom I know as much as I know about corn plantation which is, guess what, nothing.”

“No 'Ony!” Peter said, totally unaware of the topic the team was discussing, looking at his mentor with sad eyes. “Don't be sad.” the child let go of the pizza slice in his hand and reached for Tony from his high chair, making grabby hands.  
The man’s gaze softened as he took the toddler and placed him on his lap, only for Peter to hug him as tight as a two-year-old could.

“Feel 'etter?” the toddler asked after a few seconds looking up at the man. Tony smiled.

“Yeah, buddy. Thanks.”

**Notes for the Chapter:**

> I don't know how it is in your country, but in mine, meals are important.   
You always eat together with your family because it's a good way to bond with others and share experiences.  
Also, pizza is good and Peter has the biggest heart.


	5. A peaceful afternoon

**Summary for the Chapter:**

> Peter and Tony spend the afternoon together.  
A lot of fluff and a few Pepperony moments here and there.

Chapter 5

After lunch, all of the team members went back to their routine activities, leaving Tony and Peter alone again. At that point, the billionaire headed to his lab with Peter; of course, he knew that it could be dangerous to take a child there, but Stark Industries didn't run itself. Plus, he wanted to find an antidote as soon as possible. So Tony placed the toddler on the couch where he could keep an eye on him and showed him a newly washed LEGO Duplo set. 

That was enough to entertain him for about two hours -although Tony honestly expected it to last no more than twenty minutes, but apparently Peter's passion for LEGOs was there even as a two-year-old- and so the inventor could focus more on one of his own projects.   
It was nearing three o'clock when the man felt a gentle tapping on his knee, and when he lowered his gaze, he saw the child looking at him with wide and trusting eyes.

“What's up, Pete?” Tony asked while he put the screwdriver down on the table.

“Pway?” the man looked at the toddler with a confused expression, then understood.

“Oh, you want me to play with you?” he asked. Peter nodded, showing some LEGO pieces he had in the other hand.

“Do you want me to build something for you?” Another nod, followed by a little smile.

"Well, I'll have you know that I'm an inventor, so I'm pretty good at this stuff. Get ready for the best LEGO creations ever!" Peter giggled and ran back to the couch while Tony washed his hands and then sat down next to him. The billionaire built -or tried to mimic- everything the child asked for including an airplane, a dog, and a house.   
While building with the mini-blocks he realized that if Peter still enjoyed playing with LEGOs he must remember playing with them as a fifteen-year-old, and it had to be very strange for a toddler to have the memories of a teenager. So, while he was constructing a car, he decided to investigate.

“Hey, Peter, how old are you?” the child looked at him and showed two fingers.

"This many!" he said with a proud smile. 

“But you weren't always this small, right?”, the child nodded.

“I was big.”

“Yeah, that's right. And do you remember being big?” another nod.

“I go to school an' pway wif Ned an' fight bad guys!” Peter said excitedly. 

“Yes, because you’re Spider-Man.” Tony confirmed, but then another idea crossed his mind. “Hey bud... you know last time you were Spider-Man and a bad guy made you smaller.” Peter nodded, “Do you remember him?” he asked hopefully. The child scrunched up his face in concentration.

“He is vevy big and have an ouchie here!” he said pointing at his left eye.

"An ouchie? You mean like a scar?", the billionaire asked and the toddler nodded in response, "Well, that's interesting." Tony said thoughtfully while putting the last brick on the LEGO car and showing it to Peter, "What now?"   
"A dinosaur!" Peter shouted out happily. This went on for another half hour, but this time when Tony asked what to build next he received no response from the child. He glanced over to see Peter sound asleep, his weight fully on his mentor, with a peaceful look on his young face. The billionaire smiled fondly down at him as he wrapped Peter in a blanket to let him sleep, before going back to his work. 

A few hours later, the lab doors opened to reveal Pepper Potts, the most wonderful woman Tony had ever seen. She approached him and gave him a sweet kiss before asking, “How's it going down here?”.

"Wonderfully. I'm almost finished with this project." 

“What about Peter? FRIDAY told me what happened, is he okay?” Tony smiled; he knew that, despite being busy with the company, Pepper had grown fond of his protègè, too.

"You can check on him yourself he’s right there sleeping on the couch." he said nodding towards the lump of blankets on the sofa. Pepper approached the bundled child silently, sitting next to him. When she noticed Peter frowning in his sleep, she began rubbing his back soothingly and the toddler visibly relaxed and began sucking his thumb. 

“It's almost six.” she noticed, “Maybe we should wake him up, or else we won't be able to get him to fall asleep tonight.”

“You're right, as always.” Tony answered stretching out his back, “I'll give you the honor; I have to finish up over here.” he added, gesturing at the hologram in front of him. Pepper nodded and gently picked Peter up with his blanket and sat him in her lap.

“Hey honey, it's time to wake up.” she whispered while running her hand through his hair. The child groaned slightly and turned his head hiding it under the blanket, but then slowly opened his eyes and raised his head from the woman's shoulder. When his sleepy eyes finally recognized her he smiled widely.

"Peppo!" he said happily. The woman smiled back hearing how the toddler pronounced her name, then stood up with him in her arms and headed toward her husband. 

"Hi, Peter. You had a good nap, yeah? Now we can do something together before dinner, what do you say?" Peter's smile grew even wider, but suddenly his smile dropped in alarm as he seemed to realize something. 

“What's the matter?” the woman asked quickly in concern.

“Potty!” Peter announced with a certain urgency.

"Oh, in that case, it's your duty, Tony; it's boys' business." 

"Pronto!" the man said washing his hands, and then he took the child from his wife and ran toward the bathroom where the potty had been placed. Once there, he put Peter on the floor and helped unbutton his pants, then the toddler did the rest on his own, sitting on the potty and singing a song that sounded awfully like Baby Shark. 

“All done!” he declared proudly after a minute, so Tony helped him redress and wash his hands.

“Okay, now that the potty break is over we can focus on other things. What were you thinking, honey?” The billionaire asked walking out of the bathroom with Peter settled on his hip.

“Oh, nothing special. I thought we could show Peter some of the toys Bucky and Nat bought for him. They’re all clean now.” an excited squeal left the toddler as he continuously bounced in Tony's arms all the way up the elevator and to the communal living room.  
There, Natasha joined them to play with the Avengers action figures and some RC cars. Bruce, Bucky, and Clint joined after a while once they heard the excited laughter and sound effects coming from the living room.   
It was a nice moment. Domestic, even.  
Peter's laughter filled the room and every adult had big, fond smiles on their faces.

Once dinner time came around, they all sat together talking casually until Peter began to whine and thrash in his high chair. 

“What's the matter?” Tony asked.

“Down!” the child complained.

“You wanna get down?” the answer was a frantic nod followed by another whine and grabby hands toward the genius. 

"You didn't eat a lot though." Bruce observed after noticing half of Peter's rice still left on his plate. He hadn't received as much as the others, of course, but what he ate was still not enough for a child his age. The toddler, though, seemed to think otherwise, because he whined again and pushed his plate away, looking desperately towards his mentor. Tony sighed and stood up, taking the child from the high chair before returning to his seat. Peter curled up on his lap hiding his face in the man's t-shirt and grabbing it with a tiny fist. Meanwhile, the genius watched on with a questioning gaze, and when he looked up he saw that his teammates and Pepper had the same expression on their faces. 

All but Clint, who tried to reassure everyone with, “Don't worry too much, guys. He must be tired. From what you told me, last night was really tough for him.”

"Yes, you're right." Pepper supported him, and with that, they all resumed their previous conversations. 

**Notes for the Chapter:**

> This story is really slow: in 5 chapters I wrote about the first day, so tell me if you'd like it to speed up a little. Anyway, I was planning the whole thing to occur in about two weeks, including the re-aging thing, so if anything I would just summarize a day or two.


	6. A busy day for a certain Spidey-Tot

**Summary for the Chapter:**

> Peter spends his day with the Avengers while Tony works on the antidote.

**Notes for the Chapter:**

> So... Many of you asked for some Mama Spider and Peter fluff. here is a taste of it, as well as a little angst. enjoy.

Chapter 6

That night, the team opted to watch a comedy so they wouldn't ruin the lighthearted atmosphere. Peter, who had fallen asleep on Tony's lap during dinner, slept during the whole movie in Pepper's arms.  
Half away through the movie May called to check on Peter, ask if there was any news about the antidote, and to remind Tony that school would be starting again in two weeks after winter break.  
After the credits began to roll, everybody went to their respective rooms and Peter was put in his crib -built by Clint and Bucky during the afternoon- that was placed in his usual room.  
Once they returned to their room, Pepper and Tony began to get ready for bed, too, but the woman noticed that her husband seemed a little tense. 

“What's going on in that genius head of yours?”

"Uh? Nothing, I'm only stressed, like every other businessman." 

"Tony Stark stressed? That's a new one. Maybe the word you are looking for is 'worried', considering that your mentee got de-aged." 

"You know me too well, Pep. Sometimes I feel like you know me better than myself." The woman laughed lightly and began massaging her husband's shoulders. 

"It's going to be alright, Tony. You'll fix this like you always fix everything." 

“Yeah... But, in the meantime? I can't take care of a child, hell, without you I couldn't even take care of myself! I'll ruin this because I'm not good at people and, sure, I was afraid before, but now that he's this... fragile, I'm afraid I'll hurt him in some way, whether it be by saying or doing the wrong thing.”

“Tony, that child has always looked up to you. No matter if he's 2 or 15, nothing's gonna change that. He looks at you like his only goal in life is to be just like you. So relax, be yourself, and everything will be fine. You could never let him down.”  
The man sighed deeply, laying on the bed as he was guided by his wife, who did the same.

“Thanks, Pep. You always know what to say.” he whispered right before he fell asleep.

.  
.  
.

The next day, Pepper was up early for some important meetings, while Tony took advantage of the morning to work on the antidote, leaving Peter with Natasha, the only one among the present Avengers that didn't have something scheduled. So the spy and the child found themselves building the LEGO Duplo farm in the communal living room after they had breakfast. 

“How is your part coming along, Little Spider?”

“Good!” Peter said showing her a bunch of building bricks put together without judgment. The Black Widow smiled and went back to building the roof. The more they built, the more Natasha found herself supporting the toddler, that gradually began to lean on her, till he became a dead weight. Smiling fondly at the toddler, she sat on the couch with the sleeping child on her lap and began reading a book.  
Halfway through the fifth chapter, though, Peter began thrashing around and whining slightly, taking short breaths and hiccuping. Trying to calm him down, the spy begun running her hand through his hair while rubbing his back soothingly. 

"Shhh, it's okay, Little Spider." She whispered, but it didn't seem to calm him down any. After a few minutes of crying, Peter woke up with a yelp, sobbing desperately. He clung to Natasha as she stood up and began pacing the room, rocking the child back and forth. She kept whispering reassurances until the sobs became occasional hiccups and the cries subsided. 

"Did you have a bad dream, Little Spider?" she received a little nod as an answer. "And what did you dream about?" Teen Peter was very reserved, so he never talked about his nightmares, although they all knew he often had them, and on some occasions, they had also grasped how terrifying the dreams were. Maybe, though, little Peter wouldn't hold his tongue. 

“Bad bird-man.” The child whispered back, tightening his grip on Natasha.

“You mean the Vulture? The one that stole alien technology?” the toddler nodded again and hid his head under the woman's chin. She hugged him firmly, knowing what happened between the two thanks to Tony; she could only imagine how much the man had to insist to pry the whole story out of the teenager. Peter always tended to talk too much, but only about the less important things.

"Don't worry, Peter. He can't get you. We are here to protect you. You're safe." only with those words did the toddler relax in her arms smiling slightly as he wrapped his little arms around her in a hug. 

.  
.  
.

After the nightmare, Peter was tense and clingy for the whole day. He only wanted to be held, bursting into tears as soon as someone put him down. The Avengers -including Cap, Sam, and Rhodey who all came back that morning- weren't able to do anything but hand the child to each other for the whole afternoon. First, the toddler sat on Bucky's shoulders while the Winter Soldier went jogging, then, he sat on Sam's lap while he talked with some veterans, until he found himself in Clint's arms, who was assigned the essential task – at least that's what Cap called it- of going shopping.   
The man was pushing a shopping cart with one hand, while the other held Peter as he sucked his thumb with his head rested on the hero's shoulder.

"Earth's mightiest heroes my ass..." Clint murmured while he chose the cereals -not too sugary for Cap, but with chocolate for Natasha. Peter whined slightly, trying to cling impossibly closer to the spy. 

"Yeah, I know, right? This isn't the kind of mission one would expect when asked if they want to join the Avengers. I mean, I wasn't even trained for this!" The child answered by climbing closer to the man's neck and resting his head under Clint's chin. That's when the spy realized the heat radiating from the toddler's forehead and, with a little jolt, he pushed him away to take a look at him. His eyes were glassy, his lips dry, and he was pale except for his cheeks, that were a little flushed. 

"Oh man, Tony's gonna kill me because of this little stunt of yours, kiddo." he said, putting a hand on the child's forehead. He was warm, but not dangerously so. Despite this, Peter's eyes were unfocused and his lips were slightly parted, meaning that he couldn't breathe properly either. The child was also swaying a little, so Clint gently pushed him back against his chest, threw a Cocoa Krispies box in the cart -screw Cap, Nat was scarier- and pushed it to the cashier's desk.  
After he paid, he headed toward his car, zipping Peter's jacket and putting a wool hat on his head before they went out.   
He put the shopping bags in the trunk and then proceeded to buckle the Toddler into his car seat, even though the child didn't look happy about unlatching from the man and began to whine with fat tears streaming down his cheeks. 

“I know, I know, but I can't drive with you on my lap, I thought we went through this on the way here. Here-” he said, reaching for a teddy bear almost as big as the child in the other seat (Speaking of, how did it even get there? His kids surprised him more every day.) “-take this” he put the stuffed animal on the child's lap, and the toddler didn't hesitate in squeezing it, calming down. Clint was able to fasten Peter's seatbelt, get in the driver's seat and, after fastening his own, call Tony while he got in the main road.

"Clint? What's up? I'm a little busy right now." The genius's voice came through the car speakers, "Actually, you know what? Call someone else. FRIDAY found a matching name for the bad guy thanks to Peter's description and the suit footage; plus, I'm trying to figure out an antidote before that weird stuff evolves and Peter's healing factor can't fight it anymore." 

“Yeah, about that...”

“Ah, the munchkin is with you, right? Is he doing okay? Nat told me he had a nightmare.”

“Well, not really-”

“Oh, I gotta go. FRIDAY's just finished with an important analysis. See ya tonight!” Clint sighed as Tony hung up, and he looked in the rear-view mirror that showed Peter fast asleep clinging to the teddy bear.

“Don't worry, little guy. If Daddy Tony is too busy making you re-grow up, then there's Uncle Clint can handle this kind of thing.” He said with a soft voice as he kept driving.

**Notes for the Chapter:**

> As you can see, I try to throw in your requests as well, so don't be shy: ask me what you want to see!


	7. Peter is sick.

**Summary for the Chapter:**

> Clint gets Peter home and Steve helps him to deal with the sickly toddler. Tony has a parental crisis.

Chapter 7

When the car stopped in front of the compound, Peter was sleeping deeply.  
Clint took him from his car seat and carried him inside, noticing that the child's temperature had risen during the car ride.

“FRIDAY, where's Tony?” the man asked as soon as he entered the living room.

“Boss is currently in his lab, he asks not to be disturbed unless there is a, and I quote, 'alien ass-kicking emergency’.”

“Well, can you tell him as soon as he is done we need his help over here?” Clint scoffed, “And while you're at it, can you also take Peter's temperature?” there were a few seconds of silence, and then the AI answered.

“Boss has been informed, and Peter's temperature is currently at 101.3 degrees Fahrenheit.”

“That's not exactly good news, but we can work on it.” The archer stated, heading towards the kid's bedroom. He quickly undressed the toddler, leaving him in his underwear so the clothes wouldn't warm him any further before laying him gently in his crib.  
Being careful not to make any noise, the man headed toward his own bedroom, where he was able to find a box of children’s Tylenol in his first aid kit. Then, he walked to the kitchen to grab some crackers for Peter; before the child could take the medicine, he needed to eat something.

He hated to wake the munchkin up, but it was necessary to make his fever drop, so he went back in Peter's room and ran his free hand in the child's hair, followed by a gentle shake to wake him. The toddler began sobbing as soon as he roused, trying to escape from the cold hand that was touching him by rolling around in the crib in discomfort.

“Pete? Hey, buddy. Shhh, everything's fine. I know, I know... You feel like shi- ehm- you feel really bad right now, but if you eat this cracker and drink this very good syrup you'll feel better. Can you do that for me? Last effort, I promise.”

At the sight of the cracker, the child whined loudly and pushed it away, then crawled to a corner of the crib and curled up there, shivering. Clint put everything on the side table beside him and reached for the toddler, but as soon as he touched him the child let out a yelp, sobbing even harder. The man retracted his hand as if he had been burned as soon as he heard the sound, slightly taken aback from Peter's reaction. He needed help, and there was only one person who was gentle and calm enough that could deal with a sick spider-child.

“FRIDAY,” he said, but when he saw the toddler flinching he lowered his voice to a whisper. “Where's Steve?”

“Mr. Rogers is currently in his living quarters.”

“Can you ask him to come here? I need his help.”

“Right away, sir.” 

Not even a minute later, Captain America stood at the door's threshold.

“Clint? What's the matter?”

“Shhh! Peter's sick, Stark closed himself in his wonderland, Banner left for a conference a few hours ago, and the kid won't eat the stupid cracker!” the archer answered in a whisper, almost in a whiny tone.

“I'll see what I can do.” the super-soldier whispered back, closing the distance between himself and the child's crib 

“Hey, Peter.” he said in a barely audible and incredibly gentle voice. Hearing his name, the toddler lifted his head from his arms just enough to look in Steve's direction.

“Seeb?” he weakly whispered, and the super-soldier smiled warmly at him.

“That's me. Now... Why don't you eat that cracker? It has to be delicious.” The child shook his head and whined. “I know you aren't feeling really good right now, but eating can make you feel better.”

“No!” Peter cried, hiding his head back under his arms, still shivering. So the soldier put his hand on the toddler's back, that was so small that Steve's right could almost cover it all, and watched as the hiccuping child immediately relaxed. Cap then slowly took the blanket from the crib and wrapped it around the child, picking him up and hugging him strongly. That did the trick, because Peter went completely lax in his arms, sighing in relief, and then accepted the cracker that Clint offered him hesitantly. He held it with a small hand that emerged from the blanket, and sucked at it slowly, with his eyes closed.

Clint looked at the captain dumbfounded, and Steve answered with a smile, “Before the serum, I used to get sick all the time. I remember that, as a child, sometimes I was so out of it that I couldn't understand what was happening around me, but being squeezed in something made me feel safe when I was disoriented.” 

“Well, now I know who to call when the kids are sick and Laura is out of town.” the super-soldier laughed a little, and petted Peter's head.

“Come on, let's give the syrup to the munchkin and then have dinner. Rhodey will be excited to tell us all about the mission.”

.  
.  
.

Dinner consisted of spaghetti with meatballs and was peaceful, with Rhodey animatedly describing how he and Sam disarmed a bomb in the middle of nowhere while the others pretended to be interested. By the time Tony appeared from the elevator, with bags under his eyes and his clothes spotted all over with chemicals, every dish was already empty.

“Oh, look out! The iron-bat left his cave!” Sam joked, “Well, you're late; spaghetti time is over.”

“Very funny Bird Brain, but the only thing I need right now is coffee.” The billionaire replied turning on the coffee machine and only then looking around, realizing that someone was missing. 

“Is Peter already sleeping?” At that question, the room fell silent as the team stilled and exchanged weary glances. Finally, Steve got up with a sigh and approached the billionaire, placing a comforting hand on his shoulder.  
“He's... not feeling good right now. He's sleeping in his room.” Tony's features were immediately filled with concern and fear.

“He's sick?” The super soldier nodded.

“He has a fever, but we gave him some children's Tylenol, so he should be feeling better in a bit.”

“And nobody bothered to tell me?”

“Well, we tried, but clearly this doesn't reach an 'alien ass-kicking' level of emergency, as your AI told me.” Clint chimed in. At those words, Tony sighed and sat down on a vacant chair, putting his face in his hands.

“Great. Simply amazing. I've had that child for two days and I already screwed up. I knew I shouldn't have accepted to take care of him, and yet...” He sighed again and ran his hands through his hair. The mechanic was about to fall into the dark corner of his mind when he felt a hand resting on his shoulder and looked up. All of his team - his family - was surrounding him, looking at him with soft, but serious and determined expressions.

“Tony,” Cap, the owner of the hand on the genius’s shoulder, began speaking, “it's not your fault, you couldn't have predicted-”

“Yes, I could have, and I did!”, the billionaire murmured, “I knew the substance was going to evolve, but I wasted time, and I locked myself in the lab when Peter needed me the most, just like my-”

“Tony!” Steve interrupted loudly, growing frustrated with his friend's guilt complex. “Now listen to me and let me finish. Was it you who stabbed the kid? Was it you who poisoned the blade and infected him?” he waited till the genius slightly shook his head and then continued. “Then it's not your fault, and it never was. Actually, without your help Peter could already be...”, he sighed to avoid saying that horrible word, “...the point is, you're trying, and that's the best everyone can do, and everyone is doing.”

“We are all in this mess together, Stark.” Sam chimed in.

“That's right, and no one has any intention of giving up” Bucky added.

“You're not alone, Tones.” Rhodey assured him placing a hand on his best friend's free shoulder.

“We'll find a solution. Together.” Cap concluded, and Tony couldn’t help his small smile of relief, feeling a sense of gratitude for his big family. For a second, everything seemed frozen in a moment of calm and trust, until FRIDAY interrupted it.

“Sir, Peter is awake and in distress.” Everyone paused for a moment, taking in FRIDAY’s announcement, before rushing to the child's room.

**Notes for the Chapter:**

> sorry guys, it's been a long time, but the next chapter will be up soon!  
Tell me what you think and feel free to ask questions or give prompts...  
And I also have an official Instagram account where I post updates on my fictions and some (Bad) fanarts of my own, so come and follow me there!  
@_cheeksmile_fanfic.fanart  
Bye!


	8. you scared me to death, kiddo.

**Summary for the Chapter:**

> Peter's conditions get worse, but the team is always there to help.

Chapter 8

As soon as the team reached the hallway, they could hear the full-throated, deafening screams coming from Peter's bedroom that made them run even faster. Once they reached the door they saw the toddler standing upright, strongly gripping the crib's bars and shaking them with his face as red as a tomato from the crying and screaming. Peter didn't give any sign of having seen the adults in the room, he just kept shouting at the top of his lungs. Tony was the first to take action, running to the child and scooping him up. 

"He's burning up!" He told the team, alarmed, noticing how warm the toddler was as soon as he was in his arms. Peter was grasping tightly to Tony's shirt, still screaming with his head tilted backwards and his eyes shut. 

"Bath, now! We have to cool him down!" Cap ordered, and Clint and Nat ran in the bathroom. "I'll phone Bruce and ask him what to do." he added as he ran out of the room. Tony was left to bounce Peter lightly, trying to calm him down while he shushed him. The child's cries didn't falter, and the men in the room feared that he would make himself sick if he didn't stop sobbing so hard. Sam tried to make funny faces and Bucky sang some song from the forties, but nothing seemed to calm the toddler down. Finally, Clint came back announcing that the bath was ready and the genius took Peter to the bathroom. 

It took five of them to undress the child.

Rhodey kept Peter's arms still, while Bucky did the same with his legs as Natasha and Tony took off his clothes and Clint kept Peter's head from slamming into the sink's counter top where they had lain him. After ten minutes of struggling, Peter was finally naked, and Tony - taking a deep breath and whispering a quiet 'I'm sorry, kid' - lowered the toddler into the cool water. Peter screamed. A piercing high-pitched sound that hurt the heroes' ears and hearts. They couldn't hear anything but the child's cries for ten minutes straight. Then Cap came in the room, followed suit by Bruce. 

"Sorry for the delay, guys. I came as soon as Steve called, but the traffic was awful." The scientist panted, his words barely audible over the toddler's screams. He slowly approached the bathtub and knelt beside it; he leaned over and took Peter's temperature, checked his heart and breathing - Cap had to step into the tub to keep the child still - and then stood back up. 

“You can take him out, now.” He motioned to Tony, who had been holding the toddler by his armpits to keep him from falling under the water. The genius did as he was told and enveloped Peter in the towel that Clint was handing him. The child's cries had subsided as soon as he was out of the bathtub, and he was now hiccuping with his face hidden under his mentor's chin.

“So?” Sam asked.

“Well... As you all probably figured out, the poison evolved.” Bruce stated, earning concerned murmurs from his teammates. “But! FRIDAY sent me the results of the experiments that Tony's done today while I was in the car, and it looks like you've found the solution. The antidote you synthesized works. Congratulations, Tony.” the billionaire looked a little surprised, but he was fast to shrug the emotion off.

"Yeah, well I'm a genius, aren’t I?" He said walking back in Peter's room. "Now let me put some clothes on him and then we'll give him that syrup. Strawberry flavor, because I was able to do that, too." He added, signaling to the others with his free hand to get out of the room. The rest of the team did as they were told and went back into the kitchen. 

As soon as they were all out of the room, Tony sighed and sat on Peter's bed, squeezing the child in his arms in a tight hug.

"Jeez, kid. You scared me." he murmured, drying off the toddler's hair. Peter answered with a sniffle, while he rested his head on the man's shoulder, eyes closed. "Don't do that again, alright? I have a heart condition." Tony stood up and headed to the closet to pick out a onesie and some underwear for the child and then proceeded to dress him up in the comfortable outfit. After that, the two headed to the kitchen to meet the others. Peter still felt too warm for Tony's liking while he carried him, but knowing that they had a solution to their problem made the inventor feel slightly better. 

In the kitchen, Bruce was already ready with a spoon full of syrup that the toddler accepted easily in his dazed state. In fact, a few minutes later the child was fast asleep on Tony's lap, while the team watched a movie on the big couch in the common room. The rest of the evening proceeded smoothly, the group chatted quietly for a while before everybody headed to their rooms for the night. 

Tony was walking slowly to his own room as to not startle Peter, still secure in his arms, when the elevator dinged and Pepper came out.

“Hey, honey.” she greeted him. Walking closer, she noticed Peter's sleeping form and chuckled “He's out cold, isn’t he?” she cooed at the child, caressing his cheek lightly.

“Yeah.” the man confirmed, tightening his grip on the toddler and looking at him with sad eyes. Pepper, of course, noticed her husband's concern.

"What's wrong?" she asked, rubbing Tony's arm with her gentle hand. 

"The virus evolved, and he got one hell of a high fever. Practically scared us to death." Tony sighed, petting the boy's hair. 

"He seems to be doing better now, though." his wife noted. 

“I found the cure, so he'll heal now, and hopefully he'll regrow, too.” 

“That's amazing, Tony!” Pepper said and she kissed her husband lovingly. “Why don’t we head to bed now; it's getting pretty late.” she was tired after a day full of meetings and she knew that the genius was too with the day's events. She noticed that he didn't seem to be happy about the idea of resting, as he was eyeing Peter with concern.

“Maybe he should sleep with us, just in case something happens during the night.” She offered, more because she knew that Tony wouldn't be able to sleep if he wasn't sure that Peter was fine.

“Yeah, sounds good to me.” the man agreed, relieved, and they walked together to their room. They got ready for bed and slipped under the covers, placing the toddler in the middle, and fell asleep.

**Notes for the Chapter:**

> this was a little short, but I hope you enjoyed it anyway. 
> 
> don't forget to check out my Instagram account for fanarts and updates on my fanfictions:   
https://www.instagram.com/_cheeksmile_fanfic.fanart/?hl=it


	9. Who's the mole?

**Summary for the Chapter:**

> Cap and Natasha make some interesting discoveries, while Peter spends his time with his mentor.

**Notes for the Chapter:**

> Sorry for the delay, I have no excuse.  
It's been over I month, but I hope you didn't forget what happened until now in the meantime. I promise I'll try to be faster with updates... 
> 
> Enjoy!

Chapter 9

The following morning was pretty uneventful. Bruce gave Peter another dose of antibiotics and took a blood sample to see if the virus was regressing, then he recommended rest and quiet time for the toddler so that his body could heal better. Peter was still a little under the weather with his temperature still higher than normal, but only slightly, so the scientist said there was no need to worry. Tony, relieved, decided to spend his day with the child in case something happened, and so they opted to watch some cartoons and play with LEGOs while the rest of the team began to research the criminal that de-aged the kid.

It was around eleven when Natasha and Steve came storming into the living room, just as Peter finished his LEGO house.

“Tony,” Nat said to gain the man's attention, “We think we found him.” The man in question shot up from the couch as soon as he heard the news, leaving Peter to his cartoons, signaling to the spy and the supersoldier to go in the kitchen so he could hear what his teammates had discovered far from the child's ears.

“Tell me.” He said, impatience obvious in his tone.

“He is a certain Nicholas Monroe, who calls himself The Mole.” Cap explained while Natasha pulled out some pictures and a file with all the information they had found during the day.

“We still don't have a lot on him, but FRIDAY compared his face with Karen's footage and Peter's description. It really seems to be our man.” Tony looked at the picture carefully, and he could clearly see the scar Peter told him about. The Mole was very tall too, as the toddler had said, and had black, short hair. He was in his 40s, from what Tony could tell, with a few wrinkles on his pale face.

“Well, he really does look like a criminal.” the genius stated.

“Yeah. He's been in jail many times before, too. Murder, armed robbery, pushing... he has a long curriculum.” Natasha read from the papers in her hands. “Though he seems to have disappeared from the police radars lately. His last crime dates back to two years ago.”

“So why would he start back after so long? To de-age a teenager out of everything else.” Steve asked, confused as to how a man could do something so horrible like messing with a kid's life.

“Maybe he was recruited.” Tony suggested.

“You're saying that he's working for someone?” Cap inquired.

“Well, his files say he didn't even graduate from high school, he couldn't have possibly created that poison alone. Plus, if he really stopped being a criminal two years ago, he shouldn’t have any interest in getting rid of Spider-man.” the billionaire explained.

“But someone more powerful surely does.” Natasha concluded.

“Exactly. They just needed someone to do the dirty work.” As soon as Tony said those words, he felt a tapping on his leg, and he looked down to see Peter looking at him expectantly. They were so engrossed in their conversation that they didn't hear him coming.

“What's up, bud?” the genius asked in a friendly tone. The toddler lifted his arms up and made grabby hands, but Tony raised his eyebrows, pretending to not know what that meant. “Use your big boy words, Pete.”

“Up!” the child whined, jumping impatiently. The billionaire picked him up, a little confused. Peter had never been whiny like this. He was always polite and kind, just like his teenage self. The genius and his two teammates watched carefully as the child got comfortable, rested his head on Tony's shoulder, and then closed his eyes.

“Maybe we should go.” Cap whispered, “We'll call you as soon as we find something else.”

“Yeah, you'll be the first to know. See you later, Tony.” Natasha said, and then gently caressed Peter's head so the child blinked up at her. “Bye Spiderling.” she whispered with a small smile. The toddler smiled too and answered with a sleepy 'Bye-bye', then the spy and the supersoldier were gone, leaving Tony with a cuddly spider in his arms.

“Hey, Pete? Do you want to take a nap in your room?” the genius asked in a whisper, bouncing the child up and down in his arms gently. Peter shook his head slightly and grasped the front of the man's shirt.

“No? You look pretty tired to me.” The child answered with a little whine and hid his face under the man's chin, throwing his arms around Tony's neck.

“What do you wanna do, then?” The billionaire was a little taken aback from the toddler's behavior; it was strange to see him so calm and silent, as he was usually a ball of energy that could talk a mile a minute. He hoped it was only because the child was still recovering and not a strange side-effect from the virus.

“'tay wif you” the little boy mumbled, warming Tony's heart. The inventor brushed back Peter's hair and resisted the urge to kiss his head. He hummed quietly then began walking toward his office, holding the child tightly.

“Okay, then. I can work on my emails while you take a nap on me, what do you say?”

.  
.  
.

Tony worked in his lab for a few hours, with a sleeping toddler latched onto his chest. He signed some papers for S.I. and then began to do more research on the virus.

“Boss, comparing all the data we have found, I was able to predict Peter's re-growing time as you asked me.”

“Good girl. What did you find?”

“According to Doctor Banner's research, Peter's healing factor will gradually rid his body of the virus with the help of the antidote you discovered. I compared this morning's blood sample with the one you took yesterday, and the virus levels in Peter's system have lowered from 80% to 76%. At this pace, he should be totally virus-free in about 8 days. Doctor Banner also thinks that from now to that moment Peter will wake up every day two years older than the day before.”

“Thank you, dear.” Tony felt better knowing that this situation was going to be put right very soon. Everything was going to be alright, he would have his teen Peter back in no time. He leaned back in his chair with a sigh and petted the toddler's head. The boy's presence on his lap was comforting, a warm weight that made him feel somehow safe and at home. Yes, he was in his lab, he owned the place, but there were times he just felt like he didn't belong. Though, whenever the kid was with him, with his star-stuck eyes and excited voice, Tony felt proud of his lab, his house, and his Industry. For once, he felt proud to be Tony Stark. Peter always made him feel like he had hung the stars, and the famed genius, playboy and philanthropist wouldn't know what to do if something happened to him.

He looked down at the sleeping child and smiled at his peaceful expression. Damn, the kid was making him soft.

“Boss,” FRIDAY said in a low voice, as not to break the moment, “Ms. Potts would like to let you know that lunch is ready.”

“Tell her we'll be right there.” the billionaire whispered back standing up and cradling Peter in his arms, “And order some clothes for a 4-year-old, will you?”

“Of course.” The A.I. answered as Tony made his way out of the lab to meet the others in the kitchen.


	10. Thor has all the answers.

**Summary for the Chapter:**

> Thor gets on Earth and seems to bring with him all the answers to his teammates' problems. Too bad not all the answers are good o ones.

**Notes for the Chapter:**

> hi!  
I'm really really sorry this took so long, guys. I have no excuse, but I hope you'll forgive me when you read this chapter! Thanks for your kind comments and for your support!

Chapter 10

After lunch, everybody went back to their routine. Sam and Bucky trained in the gym, Bruce closed himself up in the lab, and Rhodey had a conference with the secretary of defense...

Steve and Natasha had left in search of The Mole with the plan to interrogate him after they had discovered that he could often be found wandering around Hell's Kitchen. Nobody has heard anything from them since. Which is why Tony was finding it difficult to focus on the cartoons him and Peter were watching; he wished he could help his teammates - and personally punch the guy in the face a few times - but he also didn't want to leave the toddler alone. Either way, he couldn't help but wonder why his friends weren't back yet. Maybe something had happened? Perhaps The Mole had more friends than they had expected? He should probably contact them and- 

“'Ony!” Peter's high-pitched voice startled the man out of his anxiety-induced trance. The child was on top of him, little knees feeling like needles on his lap and clammy hands on both of the man's cheeks. He was looking at Tony with a little -and cute- frown on his chubby face.

"Sorry, kid. I must have zoned out." The man said, composing himself and sitting a little bit straighter on the couch, "What did you want to tell me?" he asked the child sitting on his lap. 

"Look!" Peter said pointing out the window. Tony turned his head to see a stream of light coming from the sky and landing in the lawn -it had just been perfectly mowed, damn it- that surrounded the compound. 

“FRIDAY?” 

“Thor Odinson has just entered the Earth's atmosphere.”

"Thanks, darling." the man said getting up with the toddler in his arms and heading to the elevator. "You hear that, Pete? Thor came to visit." he added, bouncing the child, who was still focused on the light while it disappeared, to get his attention. As soon as Peter heard the news, his expression brightened up and he wriggled out of his mentor's arms to run in front of the elevator's doors, which opened with a ding not even a minute later, revealing an annoyed looking God of Thunder. 

“Fhor!” Peter greeted him excitedly, jumping adorably up and down with a toothy smile on his face. At first the god looked at him a little confused, but after a moment a glimpse of recognition passed on his face and then his expression became furious. He looked back up at Tony, who was a little taken aback by his behavior, and asked:

“Please, Stark, do not tell me this is Peter.”

“It is.” the genius answered with a sigh, looking at the toddler while he tried to climb Thor's leg. The god just grasped his hammer tighter, knuckles becoming white. Suddenly, he stormed toward the couch -almost knocking Peter down- and signaled for Tony to follow him.

“You may want to sit down, my friend. I have the answers to all of your questions, but it will take some time to tell you everything.”

“You mean you know who did this to him?” asked the genius while he sat down next to Thor and helped the toddler on the couch. The god nodded seriously.

"Many decades ago, a being appeared on Asgard. It hadn't a human-like form, but it didn't look completely like a monster, either. For a long time he hid on my beloved planet, transforming the mightiest warriors into children with a substance that slowly killed them. Nobody knows its name, but the Asgardians call him 'Pueris Percussor', literally 'The Children Killer'. It allied with small criminals, like thieves, that became its hired assassins. Finally after a long and legendary battle Odin imprisoned it, and Pueris Percussor was sentenced to remain in Asgard's prisons forever. However, a month ago it escaped. I've been looking for it ever since, hoping that it wouldn't hide here on Midgard. Unluckily, it looks like my worst fears came true." Thor explained as he played with Peter with the Avengers action figures the child had brought him. The toddler giggled when the god let his Hulk puppet fall on the carpet after Peter hit it with his Iron Man one, making both the men smile a little despite the situation. 

“You said it's mortal.”, Tony reasoned, “but we found an antidote.”

"Our scientists did, too. The substance we are dealing with is extremely adaptable and, while most of the time the children healed completely and re-grew, there were cases where the cure didn't work. Peter's blood is unique, and therefore his reaction to the antidote could be different from what we expect." the god elaborated, looking with an interested face at every toy Peter was showing him. Tony remained silent after that, seeming to be thinking over all of the new information Thor had just told him. It seemed an eternity before FRIDAY spoke up, voice alarmed. 

“Boss, Captain Rogers has sent a request for help. He’s requesting you bring the Hulk.” 

Both Thor and Tony shot up from the couch making Peter flinch, and began to run toward the hangar, the Iron Man suit forming around the genius as he rushed out of the living room.

“FRIDAY, alert everybody. But tell Rhodey to stay here with the kid.” Tony ordered, voice robotic coming from the suit. 

"Everybody's been alerted: Doctor Banner, Sargent Barns, Mr. Wilson, and Mr. Barton are all heading to the Quinjet and Colonel Rhodes is making his way to Mr. Parker." 

“Thanks, darling.” Tony said as the elevator's doors opened and he and Thor rushed to the jet to meet the others. Not even a minute later everybody was in their seats with Clint piloting. 

“So... what's the mission?” Sam asked.

"Nat and Cap went to find information on The Mole after lunch, and we haven't heard anything from them until we received a request for help three minutes ago. Point Break here says a certain Pueris Percussor, who somehow escaped from Asgard's prisons, is responsible for the de-aging. He hired The Mole to be his hitman, just like he used to do back on Asgard with small criminals. Now, this guy's only objective is to transform us into drooling babies and kill us all, so don't let anything sharp touch you. Got it?" Tony explained briefly. Everybody nodded as the jet took off. 

They were ready to kick this monster's ass.

.  
.  
.

When Rhodey got to the living room, it was silent. Much too silent to be hosting a two-year-old Peter Parker. 

"Peter?" the man called, looking around the room. The only answer was a wet sniff coming from behind the couch. Slowly, the colonel circled the piece of furniture and saw the toddler curled up in himself, looking in his direction with eyes wide and full of tears. It was a pitiful sight, and Rhodey found himself slowly kneeling -leg braces whirring slightly- and holding out his and. 

"Hey, it's okay, buddy.", he cooed, "It's just Rhodey.". As soon as Peter recognized him, his eyes welled up even more and he let out a sob, extending his arms towards the man. Rhodey picked him up and rose to his feet, rocking the child back and forth slowly. Peter was now sobbing hard, and his body shook in Rhodey's arms while he continued to wail and grasp the back of the colonel's sweatshirt. The man tried his best to calm him down by rubbing his back and humming slightly. After a few minutes Peter was still struggling, and Rhodey, who had already sung every childrens’ song he knew, was growing helpless. He didn't understand why the toddler had been so scared in the first place. 

“FRIDAY, what the hell happened here? Why is he crying?” he asked aloud so the AI could hear him over Peter's screams.

"It seems like Mr. Parker's reaction was caused by Mr. Stark and Mr Odinson's sudden rush to the hangar without explanation; they seemed particularly worried as they left." the AI explained calmly. 

“Is that the problem, Pete? You’re worried about the others?” the colonel asked adjusting his hold on the child, who nodded pitifully before cleaning the snot under his nose with his sleeve. “They've only gone to help Nat and Steve, they'll be back before you know it, so don't worry, okay?” Rhodey said slowly with a reassuring tone to help the toddler calm down. Peter nodded again and laid his head on the mans' shoulder, sobs slowly fading to hiccups. “That's it, buddy. No need to cry.” the colonel murmured, sitting on the couch with the child on his lap who was still grasping his sweatshirt tightly.

The man sighed, taking the remote and putting on a quiet documentary hoping it would lull Peter to sleep, and then looked at the clock. 

6.24 P.M.. It was going to be a long evening.


	11. in the enemy's hideout.

**Summary for the Chapter:**

> The Avengers pay a visit to the Pueris Percussor, while Rhodey spends the evening with Peter.

**Notes for the Chapter:**

> Hey guys,  
It's been a long time, and I apologize.  
I hope yall are doing well!  
Enjoy this chapter!

Chapter 11

As soon as the Quinjet got over Hell's Kitchen, the team noticed people running away screaming from a street where an abandoned building was on fire. The jet landed on a nearby warehouse and the Avengers swiftly jumped down heading in the direction of the fire.

“Cap? Can you hear me?” Tony asked through the comm, hoping they weren't too late. There were a few long seconds of silence that kept the team with bated breath before the distant and slightly glitchy voice of the Captain came through.

“Cap here. -Bzzz- We are in the -bzzz-ilding. Hurry.” Steve answered, urgency clear in his voice. The team didn't need to be told twice as they stormed inside, carefully avoiding the flames as they rushed to find their mates.

“Third floor. Watch out.” Natasha's voice alerted them as they made their way in, men coming out from every corner trying to stop them. At first it didn't look too difficult: they were just common criminals with guns and knives, a joke for Earth's Mightiest Heroes. But the further inside they got, the stronger and better equipped the enemies became, until, when they reached the third floor, the rivals weren't... human anymore. Not completely, at least. There were monster arms, enormous bodies, mechanical tentacles... 

“What the hell happened here?”, Sam joked, “We ruined your annual freaks reunion?”.

“Sounds like. But you could have invited us, guys. We fit very well in that category.” Tony said while blasting a few men with a lizard tails in the chest. Creatures came from every side of the cavernous room they were in, filling it almost completely. It was chaos; everybody kept throwing punches and shooting in every direction, without really knowing who was bad and who was good. The Hulk roared in anger as he threw bodies left and right. However, even among the crowd Natasha's insanely perceptive eyes found the man they had been searching for in the first place.

“Guys, I see The Mole. He's trying to reach the door.” she said while incapacitating a man with four arms.

“I'll take care of him.” Clint announced as he began chasing after him. The archer promptly aimed an explosive arrow at a pillar near the door, blocking the exit with crumbled concrete and continuing his pursuit. It was clear that The Mole knew he was too weak to actually confront an avenger and that his only objective was to escape. Clint wasn't about to let him go far though, not after what he had done to Peter. With that in mind he threw himself at the criminal and pinned him down on the ground, arms locked behind his back.

A sudden explosion rocked the ground beneath them, making their ears ring and the building vibrate dangerously causing the ceiling to begin collapsing around them. 

“We have to get out of here.” Cap ordered through the comm. 

“No. We haven't found the Pueris Percussor yet.” Tony argued. 

“Tony, this building is burning and will collapse in any minute. If we stay here, we'll die.” Steve tried to make him see reason as he, Sam and Nat made their way out.

“Don't worry. I have The Mole. He’ll know something useful.” Clint said while he pushed the criminal through a hole in the wall -probably made by the Hulk- and jumped down, Sam ready to catch them. 

“Okay, then. But it's not over.” the genius gave in, flying out and landing on the warehouse where the jet was.

“Of course not. We will come back for the monster.” Thor agreed. 

.  
.  
.

Rhodey yawned as he stared at the TV which was showing yet another documentary, this time about clownfish. He was beyond bored, and all he wanted to do was go to bed and have a good night’s sleep. It was almost midnight, after all. The problem was, he couldn't. He was physically stuck on the couch because of a certain spider baby, who had refused to let him up for the past three hours. 

After the initial scare, it had been okay; Peter had behaved, and the man had even begun to think that being on babysitting duty wasn't that bad after all. They had dinner and he had got the toddler changed in his -rather adorable- pajamas, which were two sizes bigger since the kid was meant to grow that night. A toddler in too big PJs was easily the cutest thing Rhodey had ever seen, especially since that toddler happened to have big doe eyes and chubby cheeks and, most importantly, he happened to be the kid everybody had grown so fond of since Tony had taken that same Spider-child with him to Germany. 

Pajamas or not, Peter had been slowly growing more and more restless during the evening: he kept glancing at the door every few minutes and every time he did he seemed to get more upset. Then, when the Colonel had come back from a toilet break which he could no longer push back, the toddler had disappeared from his spot on the couch where the man had told him to wait for him. After a second of full panic, Rhodey had remembered that he had an A.I. at his service and was informed by FRIDAY that Peter was in the lobby. That was indeed where the Colonel had found the toddler: trying to open the front door while crying silently. After a few minutes in which Rhodey had managed to calm the child down a little, Peter had revealed to him that he had been looking for Tony and the others because he was worried since they weren't back yet. So the colonel had sat with him on the couch once again and put on another documentary, since it had seemed to work as a soothing technique the first time. 

And that's how he had spent the last three hours as a human pillow for Peter. Every time the child looked like he had finally nodded off, Rhodey had tried to sneak out of his grasp, only to cause the toddler to jerk his head up from the Colonel's shoulder with a cry. 

“Come on, bud, it's very late. Why don't you close your eyes for a little bit?” the man tried for the hundredth time.

“No.” Peter answered firmly, eyes struggling to stay open.

“Why not?” Rhodey asked with a pleading voice.

“I wan' 'Ony.” the toddler's voice wobbled and his eyes filled with tears, this time probably more from exhaustion than from anything else.

“He'll be here when you wake up, I promise. There's no need to cry.” the colonel began bouncing Peter gently and brushed away the few tears that had fallen on the toddler's cheeks. The little one sniffled and shook his head, whining a little.

In that exact moment the front door opened and the sound of heavy boots filled the lobby and the living room, and not even a second later the team -disheveled and worn out- was in front of the couch. Rhodey stood, his expression grateful, with the toddler in his arms.

“Thank God you're back.” he said relieved. 

“'Ony!” Peter screeched, trying to wriggle out of the Colonel's arms. The billionaire was in front of him in a second, taking the child with a little smile. The toddler threw his arms around his mentor's neck and hugged him as strong as his two-year-old body could.

“Hey, Pete.”, Tony said rubbing the child's back, “What are you doing up? I know we haven't set a bedtime, but isn't it a little too late for you?”

“Well, I tried, I really did. But he refused to sleep without you.” the Colonel defended himself, earning another small smile from his best friend.

“Thanks, Platypus, I really owe you one.”

“Yep. You definitely do. Now will you guys excuse me, I've been stuck on that couch for more than my bladder can take. Goodnight.”

After that, everybody went to their rooms exhausted by the long fight. Tony put Peter to bed easily since the kid was already half asleep when they made it to his room, before taking a quick shower and laying down beside Pepper in his bed.

At almost two in the morning, all the lights in the Avengers' living quarters were out.


	12. snow day

**Summary for the Chapter:**

> the Avengers wake up to an amazing surprise... The Compound is covered in snow! better not waste this opportunity to have fun.

**Notes for the Chapter:**

> hi guys!  
I hope you like this chapter.
> 
> I'm sorry for any mistake.
> 
> enjoy your summer!

Chapter 12

Tony was woken up by something falling on his stomach. He shot up in bed and looked around frantically, trying to find his presumed attacker, until the sound of giggling made him look down on his lap. There sat a little child in Star Wars pajamas with a cheeky smile and curly hair, staring back at him with his big brown eyes. The man was confused for a moment about who the hell that child was, but then the last days' events came crashing back to him.

"Peter?" he asked tentatively. The child giggled again.

"Good morning, Tomy!" he answered cheerily, and Tony was flooded by relief. It had worked, just as Bruce had said. This was a four-year-old Peter Parker.

"Good morning to you." the man whispered, noticing that Pepper was still asleep beside him. He signaled to the boy to lower his voice and then pointed at his wife. Peter nodded in understanding and giggled a little, his index finger in front of his mouth. Tony smiled and patted the child's head, only then realizing, looking out of the window, that it was barely the sunrise. Frowning, he looked at the alarm clock on his nightstand. Six A.M. 

"Buddy, what are you doing up?" he asked then. They had all gone to bed very late the night before, so he was surprised to see the child already up after no more than six hours of sleep. Peter shrugged in response, and then slowly leaned his head on the man's chest, hugging him. Tony smiled softly looking down at the child, and then leaned back on the bed's headboard, rubbing the boy's back.

"You little twerp, you just wanted to be cuddled, did ya?" the man faked indignation. The child smiled, hiding his face in his mentor's shoulder. Tony began running his fingers through Peter's soft and curly hair, and the boy went completely lax in his hold. They stayed like that for about half an hour before the man heard a grumble from Peter's stomach and decided it was time for breakfast.

Heading to the kitchen, his mentee on his hip, Tony was met with an unexpected surprise out of the room's enormous windows. The big field that surrounded the compound, along with the trees, was covered in a thick layer of white and glistening snow. Everything was completely immaculate and silent, making the landscape look like it came from a fairytale. 

"Hey Pete." the man called the child, adjusting him a little higher on his hip, "Looks like Santa brought us an early gift while we were sleeping.". Only then did the four-year-old lift his head from his mentor's shoulder, and looked outside, eyes filling with amazement and delight. Peter gasped seeing the white landscape and wriggled his way out of the man's arms to run to the window. 

"Snow!" he screamed giggling, his little puffs of breath fogging the cold glass as he looked outside in awe. "Snow, snow, snow!" he repeated, jumping excitedly. 

"That's right, kid." Tony answered heading to the kitchen, " We can have breakfast and then have a look outside, what do you say?" he proposed while he took some pancake mix out of the counter. The child squealed in delight and ran up to the kitchen island. That's when Steve, Sam, and Bucky came in, all sweaty from their early morning run around the compound. 

"Hey, Tony. You are up unusually early." Steve greeted, not noticing Peter since he was covered by the kitchen island. 

"Well, I would have stayed in bed or headed down to my workshop, but a little troublemaker decided that six A.M. Was a great hour to jump on my chest." the genius answered, gesturing with his head in the direction where Peter was now trying to hide from the three men, hands on his mouth to stop the giggles. 

"Oh, you mean Peter? Where is he?" Bucky asked with a smile, understanding what was going on.

"I don't really know, he was here a second ago... Where did he go?" Tony said faking surprise.

"Well, more pancakes for us, am I right?" Sam exclaimed playing along. He went to the counter and added chocolate chips to the mix Tony was pouring in a pot. "Ah, yes, chocolate chips pancakes, my favorites! And since the kid is not here we could eat his, too!"

"No! Don't eat my pancakes, Sam! I'm here!" the child yelled coming out from his hiding spot. For a split second, the two super soldiers and the Falcon were a little taken back by Peter's new aspect, but they immediately sobered their expressions in a warm smile. 

"Oh, there you are, little punk!" Bucky was the first one to recover, and he began chasing the child around the living room to distract him from the conversation that was going to happen in the kitchen -he knew Steve way to well, and the face he was wearing at that moment was the 'we need to discuss a few important things' kind of face he liked to wear in the Avengers meetings. In fact, as soon as the munchkin and he were out of sight, Cap approached Tony, who was now making the pancakes in the stove, and asked discreetly:

"So... It seems like Bruce was right, huh?"

"Well, he is at least one feet taller now, so yeah. It worked." the billionaire answered while he flipped a pancake over. "But this is not what you wanted to talk about, is it?". Steve sighed and shook his head, the two of them watching Sam throw a pillow at Bucky's face, making Peter laugh like mad.

"Last night, in the building... I think I saw something.", the supersoldier started, "I... I don't even know how to describe it. It was... huge, black, cold, creepy." both the men flinched as something fragile crashed on the ground. 

"Be careful with my furniture, Wilson: it's more expensive than your head!" Tony yelled over Peter's laughs and the two men bickering about who to blame for the broken ceramic. "Do you think it was it? The Pueris Percussor?" he then asked Steve, lowering his voice so they wouldn't hear him.

"Well, as far as I'm concerned, it could be anything, really. But... I am optimistic enough to think that we will have to deal with a monster at a time, so yes. It was it." Tony sighed, piling four pancakes on each plate.

"How come no one else saw it?" he asked after a thoughtful moment.

"It was hidden behind the enormous wooden doors at the back of the room. I think all the other monsters were trying to protect it. While I was fighting, one of the lizard-men threw me against the right door, causing it to give out a little, creating a crack in the wood. I was only able to see a giant black form moving in the semi-darkness before I was pulled back in the fight by the same lizard-men, who had probably understood his mistake." Steve explained, and Tony nodded.

"Well, at least we have an idea of this Pueris Percussor guy." the genius concluded, putting the last pancake on its plate. "FRIDAY, be a dear and inform everybody that breakfast is ready." 

"Of course, boss."

Everybody slowly made their way in the kitchen, and the team had breakfast altogether. After that, Natasha headed to the detention area of the compound with Cap, determined to pry out of The Mole some useful information. All the others -except for Bruce, who claimed to hate the cold- rushed outside to play in the snow, if not for the love of the weather, only to please Peter, who had begged everyone to play with him -who could resist those puppy dog eyes?

At first, they opted for building a snowman, but, in real Avengers fashion, it slowly morphed in a huge, muscular man, who Peter named Icy. It took them a whole hour to build it, since it was almost 10 feet tall and his right arm kept falling off because Rohedy insisted on making it hold an enormous gun. But finally, after Tony built a structure with branches to sustain the arm, Thor lifted Peter to Icy's face, where the child happily put a carrot as a nose, much to Sam's dismay - "Oh come on! That stupid carrot ruins the toughness!".

After that, the superheroes split into two teams -Steve, Sam, Bucky, and Clint versus Tony, Rohdey, Natasha, Thor and Peter, who actually only stuck to his mentor's side all the time, watching and giggling in excitement- and they played snowball fight. It was more of a war, with actual attacks and withdrawals and even tranches, but it eventually came to an end after Thor accidentally buried Clint and Sam under a pile of snow. So, when Steve suggested to go for something less dangerous, and Peter proposed hide and seek, they all agreed, and Rhodey was chosen as the seeker. 

The child ran off as soon as the rules were set -no hiding inside the house or beyond the compound's limits, which were marked by red poles on three sides and the lake to the east. Making sure to be as silent as possible, he wandered around through the trees that surrounded the facility to try and find the perfect hiding spot. Tony was going to be so proud of him if he was the last one to be found, so he wanted to find the most difficult and unlikely spot where Rhodey would look for him. 

After a while, he spotted a big, twisted tree with fairly low branches in the distance. That would be a good place: he could climb until the top and wait for the others to be found while watching from up there his friends' moves. With this in mind, Peter began his trek to the tree. In this point of the patch, the snow was fresh and deep, making it difficult for a child as small as him to walk through it. Every step was a struggle, as the snow reached his hip: the 4-year-old felt as though he was swimming in something heavy and compact, and by the time he reached the tree he was sweaty and hot, so much that he decided to take his winter coat off and tie it on his hip. 

Slowly but surely, he began to climb the big tree. The branches were a little slippery because of the ice that had formed on them, but Peter managed to keep a tight grip. It took him a while to reach a big branch that he had identified as the half of the tree, and when he got there he decided to take a break since climbing was taking a toll on the four-year-old. He carefully lowered himself to sit astride the branch and took some deep breaths, looking around. Through the twisted branches he couldn't see anyone and he couldn't hear anything either. Good, that meant Rhodey hadn't got to this area yet, so he still had a bit of time to reach the treetop. After he had rested for another minute or so, Peter carefully began to stand up.

Gripping the tree's bark tightly to pull himself up, he put a foot on the slippery and frosty branch, and he was about to do the same with the other foot when suddenly he heard a loud crack and the bark piece he was gripping broke off. Frantically, Peter tried to find something else to hold on to, but he only lost his balance more. His foot slipped on the iced branch and he began falling backward, hitting his head on a lower branch before meeting the snow-clad ground with a soft thud seconds later. 

The air was knocked out of him and the child lay still for a moment, eyes wide in shock, while he tried to process what had happened. Then something in his mind clicked and he took a long, shuddering breath, slowly registering the pain in the back of his head. He lifted a trembling hand to the source of pain, lifting his head slightly, and when his little fingers came back wet with a warm, red substance his breath hitched and his eyes blurred with tears. He tried to get up, but he regretted it a soon as the word started spinning around him, and he lay back down. His head hurt, he was sore all over and the snow around him was starting to wet his clothes. He shouldn't have taken his jacket off. He shouldn't have climbed that tree. 

And so, hurt, cold and regretful, he did what four-year-olds do best. He started crying.

.  
.  
.

Rhodey had been searching around for a good two hours, and he had managed to find all of his teammates – he wouldn't admit it out loud, but three-quarters of the time had been used to find Natasha. Now he only needed to find Peter to finish the game to go inside and warm up -it was starting to get too cold for his liking out there. It had been in his plans to look for the child last, to give him enough time to find a good hiding spot, and then to make it look like he had won the game. 

The only problem was it seemed the boy had managed to find the best hiding spot in the whole estate. 

The man had looked everywhere he could think of, everywhere he believed a four-year-old could have burrowed, and finally, admitting his defeat, he had asked for the others' help. The team, who had been sitting in the benches just outside the compound while making fun of him, had immediately sobered up at the news that Peter couldn't be found, and had started looking for him. 

Now, fifteen minutes later, everybody was panicking. They were searching frantically, screaming the boy's name, shaking trees, and diving inside bushes, but it seemed like Peter had disappeared. 

"Peter!", Tony was yelling while circling a group of trees, desperately trying to slow down his breathing, "Can you hear me? Come on, kid, where are you?" In... one, two, three... and out. He couldn't panic. Not now when his kid needed him. He had to keep calm in order to find him and hug him to his chest and never letting him go. He barely registered Clint calling the child not far away from where he was looking inside a group of spiny bushes, while Nat was climbing a nearby tree. 

Cap had decided to go off in the farthest side of the park, and he was looking around silently, unlike his teammates, straining his years to hear something, anything that could give him a clue on the four-year-old's location. He was worried, actually not far from panicking himself, but yelling had never been his style. As a captain, it was part of his job to always look relaxed and confident, and while raising his voice worked to get someone's attention, it didn't make him look calm. Plus, if something had happened and Peter was injured, he didn't think the child would have liked to hear panicked screams, and it surely wouldn't help in case the kid was already panicking himself. So Cap kept walking and listening, looking around for hints. 

That's when he heard it. A sound that sounded so foreign in the wood. A muffled cry, followed by a whimper.

"Peter?" he asked, voice loud and forcibly calm. A loud sob came from behind a big tree on his right. He hurried in that direction, the cries getting louder as he got closer. As soon as he had rounded the twisted form of the tree, he saw the boy's trembling form laying in the snow, fat tears rolling down his cheeks and chest expanding painfully with every sob. The captain was at his side in an instant, taking the child's -too cold, he noted- hand while scanning his little body of any injury.

"Hey, Pete. Hey, sport. It's okay. Look at me, alright? It's okay. We found you. No need to cry." he reassured him, locking his eyes with Peter, who lifted his other hand towards the man as soon as recognized him. Steve suppressed a gasp when he saw the blood on the child's fingers, but took his hand anyway, trying to be as reassuring as possible so that the boy could calm down.

"Buddy, I need you to tell me where you are hurt, okay?" he asked, voice firm, but with a calm expression on his face.

"M-My head-d." the four-year-old managed through the sobs and the violent shivers that racked his body. Cap slowly shifted so that he could take both of Peter's small hands in one of his, and then proceeded to carefully lift the child's head with the other. He sighed in relief when he only saw a small cut on his nape. It was surely painful, but not dangerous in the slightest, so he lifted the boy in his arms and held him close, both to provide comfort and heat. Peter latched onto him, crying in the supersoldier's shoulder, while the man rocked him a little and rubbed his back. He mindlessly murmured a 'Found him' in his comm, and then went back to whispering reassurances in the child's ear. He didn't move, knowing that the others were tracking him tanks to his comm, he just held Peter while he cried, trying at least to warm him up a little bit. 

"Peter!" he heard a relived Tony yelling a few seconds later, followed by the sound of hurried steps in the snow behind them. Then the mechanic was at their side, holding out a blanket, but the captain shook his head.

"We need to get him out of his clothes first. They are soaked." he explained, while Peter threw himself to his mentor, who was luckily ready to catch him.

"T-Tomy!" the kid wailed, seeking comfort by hiding in the man's shoulder. The billionaire held him close, squeezing him in a bear hug.

"It's okay, Underoos. We got you.", he murmured, "but I need you to be brave for a little bit longer and let me take your clothes off, okay?" the child shook his head.

"N-No!" he sobbed, trying to make himself smaller in his mentor's arms. The man looked helplessly at Steve, who knelt closer tho the two of them, putting a warm hand on Peter's back.

"Pete, we know you are really cold right now, but that's also because your clothes are all wet. If we take them off, you'll be dry and it will be easier for you to get warm, okay?" he explained slowly, and luckily the child nodded his head, pulling out of the hug so that Tony could peel the layers of clothes off of his shivering body, leaving him only in his underpants. Then, the man enveloped his mentee in the blanket, he lifted him up and the three of them made their way back to the compound.

By the time they had reached the med bay to get Peter's cut checked, the boy had stopped sobbing thanks to Tony's lulling motions and comforting words, and was only occasionally sniffling, face hidden in his mentor's shoulder. The calm, though, was only short-lived, since the child started screaming again as soon as Bruce began cleaning the back of his head. 

Needless to say, the boy was exhausted by the day's events, and most importantly by all the crying, so he fell asleep as soon as the team was back in the common room, a big bandage on his nape. The task of doing lunch fell on Steve since he was a very good cook and Tony's arms were still full of the four-year-old, who had latched on to him and refused to let go even in his sleep, whining as soon as his mentor's comforting essence and body heat were out of his reach for more than half a second. 

So the rest of the day was spent lazily on the big couch in the common room, watching movies or documentaries, Peter waking up only near four o'clock, but still never leaving his mentor's side -the poor man had to rush to the toilet at some point when Clint was able to get the child distracted for a few minutes.

Then, after dinner, Tony decided to give Peter a long, warm bath with bubbles -Bruce had said he hadn't been in the cold long enough to get hypothermia, but to the mechanic's touch the child's hands were still a little cold-, then he changed him in a six-year-old sized pajamas with Chewbacca all over it and put him in bed.

"Okay, time to sleep for everybody who can't reach the kitchen counter." the man sighed, pulling the blankets higher to cover Peter's face, which caused some giggles from the child. "Close your eyes and dream about Icy the snowman beating up all the bad guys." he added when the kid resurfaced from under the duvet with a smile. His big, doe eyes were staring at him like he had hung all the stars in the sky, and at that moment Tony couldn't help but remember how scared he had been to loose that perfect child and the opportunity to see those eyes again. A shiver ran down his spine at the thought, and there, knelt beside Peter's bed, the mechanic understood for the first time all those feelings he had been having towards the kid for a while. It wasn't just concern or pride, it was love, and a special one. That particular warmth a father feels when he looks at his child. 

Peter yawned, pulling the millionaire out of his thoughts. He rolled on his side to look in Tony's direction and put one hand under the pillow, holding the blanket with the other. The mechanic began running his hand through the child's hair -being mindful of the bandage- and felt him relax under his touch. 

"Don't you ever pull a stunt like that ever again, ya hear me kiddo?" he murmured just as the four-year-old closed his eyes. "We were all very worried about you, so promise me you won't climb trees anymore, okay?" he knew, in the back of his head, that Peter would be back to climb things way higher than trees in about week, but right at that moment, the most important thing was to protect the child he had come to see as his own. And while he could still stop it, while Peter wasn't old enough to tell him no, he would keep the kid from climbing anything. Even the tools in the living room.

The child never answered, already fast asleep, but Tony would make sure to keep him safe anyway. Because he had promised himself.

**Author's Note:**

> This was it. What do you think?  
Again, if you found some mistakes you are welcome to correct me in the comments. or not. It's your choice.  
if you have some prompts write them in the comments and if I think they'll fit in the story you even might see them!  
Bye! see ya next time :)


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